package cn.tedu._05weibo.interceptors;

import cn.tedu._05weibo.pojo.vo.UserVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@Slf4j
public class LoginCheckInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        /*
            登录状态校验;
            1.获取HttpSession会话参数;
              HttpSession session = request.getSession();
            2.在会话中获取用户标识:session.getAttribute("user");
            3.判断用户标识是否为空;
              3.1 非空: 登录状态, 放行 return true;
              3.2 空: 未登录状态,
                  * 重定向到登录页 response.sendRedirect("/login.html");
                  * return false;
         */
        log.debug("拦截器中进行登录状态校验");
        HttpSession session = request.getSession();
        UserVO userVO = (UserVO) session.getAttribute("user");
        if (userVO != null){
            return true; //放行,继续执行控制器方法中的业务逻辑;
        }
        // 未登录状态,重定向到登录页面
        // http://localhost:8080/login.html
        response.sendRedirect("/login.html");
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}
